1. Field of the Invention
This invention relates to an aerator for liquids, particularly to an aerator for water, comprising at least one aerating basin, which contains a plurality of immersible elongate bodies, which are secured to the peripheries of wheels which revolve about an axis that is parallel to the surface of the liquid in the aerating basin so that each of the immersible bodies emerges entirely out of the liquid on one side of the aerating basin and is entirely immersed into the liquid on the other side of said basin, wherein the immersible bodies define internal cavities, which communicate with the outside of the immersible bodies through openings formed in the walls of said bodies. The aerator is mainly intended for aerating contaminated water, such as sewage.
2. Description of the Prior Art
An aerator of that kind has been disclosed in Published German Application No. 2638665. In that aerator the immersible bodies consist of elongate tubes having any desired shape in cross-section and formed in their walls with apertures extending around two-thirds of the periphery of the tube. The apertures are so arranged that they face upwardly as the tube is emerging out of the liquid and face downwardly as the tube is immersed into the liquid. The active surface is increased by the provision of discs, which have been mounted in the tubes and permit the growth of microorganisms in a film of activated sludge on said discs.
Hence, the invention provides an aerator for liquids, particularly an aerator for water, which comprises at least one aerating basin, which contains a plurality of immersible elongate bodies, which are secured to the peripheries of wheels, which revolve about an axis which is parallel to the surface of the liquid in the aerating basin so that each of the immersible bodies emerges entirely out of the liquid on one side of the aerating basin and is entirely immersed into the liquid on the other side of that basin. Each immersible body consists of a plurality of axially aligned discs, each of which is provided at its rim with a peripherally and axially extending flange so that a chamber is defined between adjacent discs, and each flange is formed with a slot in a portion which faces downwardly as the immersible body enters the liquid.
The portion formed with the slot preferably faces vertically downwardly as the immersible body enters the liquid. The term "faces vertically downwardly" means that said portion faces in a direction which deviates from the vertical by not more than 5.degree..
The slot preferably subtends an arc of 5 to 25 degrees. Further features and details of the invention will now be described with reference to the drawings.